Fluid pressure operated device



Filed May 17, 1943 3 Sheets-Sheet 1 wwl @en 31. 1944. C. A. 'Fm @$361,757

FLUID PRESSURE OPERATED DEVICE Filed Manr 17, 1943 3 Sheets-Sheet 2 i a s E NM Il PO w Q min 1 my@ Y l m WIW lltlH i r Il Il" www "w MH i* I Q" www ,f *Hut/U fr l! E WHW m4 m l w w 'NW WIW "I my WMM' 1S L- g uw, y?

a I "U 7 'Il W Mm I 1 as je @b Kga; W m I mgl' tmf() Q1 ||ir|r N1 J -H i *u Mil E am we jez/@122W Oct. 3l, 1944. c. A. FlNK FLUID PRESSURE OPERATED DEVICE Filed May 17, 1943 3 Sheets-Sheet 5 Patented Oct. 31, 1944 UNITED sTATEs PATENT oFFicE FLUID PRESSURE OPERATED DEVICE Charles A. Fink, ciliege-0, 111.l

Application May 17, 1943, Serial No. 487,329

1 Claim.

The present invention relates generally to fluid pressure operated devices. More particularly the invention relates to that type of device which operates to translate the pressure of the fluid into reciprocating movement and comprises acylinder with a head at one end thereof, a valve supporting head fitting against the other end of the cylinder and having a fluid inlet and a fiuid outlet, a piston in the cylinder with a rod therefor extending slidably through the rst mentioned cylinder head, means forming a duct leading from the valve supporting head to one end of the cylinder and a second duct leading from the last mentioned head to the other end of the cylinder, and a plunger type valve which is slidably mounted in the valve supporting head and operates when shifted into one position to `connect one of the ducts to the inlet and the other duct to the outlet in order to cause shift of the piston from one end of the cylinder to the other and operates when shifted into its other position to `connect the other duct to the inlet and the one duct' to the outlet in order to cause shift of the piston towards the other end of the cylinder.

One object of the invention is to provide a fluid pressure operated device of this type which is generally an improvementup'on, and is more efiicient than, previously designed devices of the same general character.

Another object of the invention is to provide a device of the type under consideration in which the plunger-type valve is shifted back and forth for piston controlling purposes by Way of a portion of the fluid under pressure entering the valve supporting head via the inlet and such portion of the fluid iscontrolled by way of a pilot valve which is slidably mounted in the plunger-type valve and is connected by Way of a lost motion connection to the piston rod so provide a uid pressure operated device of the i type and character under consideration in which Afeatures which are hereinafter set forth and are l the invention, showing the piston at one end of that it is shiitable from one position to the other at the end of each stroke of the piston.

A further object of the invention is to provide a uid pressure' operated device of the last mentioned type and character in which the valve arrangement is such that the main or plungertype valve remains in` either of its shifted positions until shift of the pilot valve by the piston rod and as a result the piston rod is always subjected to motionA or shift when fluid under pressure is delivered to the inlet and cannot under any circumstances assume a dead center position.

A still. further object of' the invention isto the cylinder and the main or plunger type valve in position to cause the uid under pressure toA iiow through the ducts in such manner as to shift the piston towards the other end of the cylinder;

Figure 2 is a similar sectional View of the device, showing the piston after shift to the other end of the cylinder, and after shift of the pilot valve into a position to cause shift of the main valve;

Figure 3 is a like sectional view of the device, showing the piston in readiness for its return stroke and the main valve in its shifted position;

Figure 4 is a longitudinal sectional view of the device, showing the piston at the end of its return or retractile stroke and after shift of the pilot valve into its other position but before shift of the main valve into .a position again to reverse the flow of fluid under pressure through the ducts and effect shift of the piston;A

Figure 5 is an enlarged transverse longitudinal sectional view of the valve supporting head', illustrating in detail the arrangement and design of the plunger type and pilot valves;

Figure 6 is an enlarged" verticaltransverse sectional view on the line E-G of Figure 1;

Figure 7' is a side view of the mainor plunger type valve; and

Figure 8 is a side view of the pilot valve for controlling shift of the main valve by a portion of the fluid under pressure entering the inlet.

The device which is shown in the drawings constitutes the preferred embodiment of the invention, and is adapted to be operated by any fluid under pressure, that is, either a gas or a liquid. It operates, as hereinafter described, to translate the pressure -of the fluid into a reciprocating movement and may be used for many different purposes. As the main parts thereof the device embodies a cylinder 9, a piston l0, a head II at one end of the cylinder, a valve supporing head i2 at the other end of the cylinder, and a plunger type valve I3 in the last mentioned head for controlling the fluid so that it operates to effect reciprocation of the piston. D

The cylinder S embodies a pair of lugs I4 at one side thereof whereby it may be supported in a horizontal position, as shown in the drawings, or attached to a suitable supporting structure and maintained in any other desired position. The piston lil is slidably mounted within the cylinder and is adapted to move back and forth in response to the hereinafter described action of the fluid under pressure. It embodies arod I5 and has a pair of piston rings I3 in grooves in the periphery thereof for sealing the space between it and the cylinder and preventing leakage of fluid from one end face of the piston to the other. The rod I5 extends through, and is adapted to slide in, a centrally disposed bore I1 in the central portion of the cylinder head I I and is of such length that the outer end thereof is always exteriorly disposed with respect to the cylinder` rThe inner or other end of the rod is externally threaded and flts within an internally threaded so-cket I8 in the central portion of thepiston I0. The cylinder head il fits against an integral outwardly extending flange I9 on the adjacent end of the cylinder 9 and is 'removably secured in place by means of an annular series of bolts 20. The latter extend through the marginal portion of the cylinder head I I and llt within internally threaded sockets in the-flange I9. The central portion of the cylinder head II is provided with a stuffing box 2| for preventing leakage of fluid from the cylinder through the centrally disposed bore I1. c

The head I2 at the other end of the cylinder is cup-shaped and embodies a cross-wall 22 and a cylindrical side wall 23. The cross-wall 22 ts within and extends transversely across'the contiguous or adjacent end of the cylinder 9 and coacts with the head II to close the ends of the cylinder. The cylindrical side wall 23 projects outwardly from the cylinder S and embodies an integral outwardly extending annular flange 24 at its inner end. This flange abuts against an integral outwardly extending flange 25 on the adjacent end of the cylinder 9 and is secured in place by means of bolts 26 which extend therethrough and flt within internally threaded sockets in the flange 25. The outer or other end of the cylindrical side wall 23 of the head l2 is closed by means of a circular cap 21 which is removably secured in place by means of an annular series of bolts 28. The latter extend through the mar.- ginal portion of the cap 21 and fit within internally threaded sockets in the outer end of the wall 23. The cylindrical side wall 23 denes with the cross-walls 22 and the cap 21 a cylindrical chamber .29 for the plunger type valve I3 and embodies a fluid inlet 30 at one side thereof, and a fluid outlet -3I at its other-side. Said side wall also embodies flve laterally spaced annular grooves 32, 33, 34, 35 and 36 in the inner periphery thereof and has a sleeve 31 between it and the valve I3. The fluid inlet 3l) is adapted to be connected by way of a valve controlled pipe (not shown) to any suitable source of fluid under pressure and communicates at its inner end with the annular groove 34. The outlet 3| is disposed diametrically opposite to the fluid inlet 30 and is adapted to have the fluid pass therethrough to any desired point after it operates in the cylinder 9 to effect reciprocation of the piston I0. It is formed in a laterally extending boss-like protuberance 38 on the cylindrical side wall 23 of the head I2 and communicates with the annular grooves 32 and 36 by way of an elongated longitudinally extending discharge chamber 39 in said protuberance 38. The grooves 32 and 36 are located outwards of the grooves 33 and 35 and the annular groove 34 is disposed mid-way between the two last mentioned grooves, as shown in Figure 5. The sleeve 31 fits snugly within the inner periphery of the cylindrical side wall 23 of the valve head I2 and abuts at its ends against the cross-wall 22 and the removable cap 21. It forms a cylindrical slideway 40 for the valve I3 and has five annular series of holes 4I, 42, 43, 44 and45. These holes extend transversely through the sleeve 31 and are aligned and communicate with the grooves 32, 33, 34, 35 and 36, respectively. The annular groove 33 is connected by a duct 46 to the end of the cylinder which is adjacent to the cross-wall 22 of the head I2, and the annular groove 35 between the grooves 34vand 36 is connected by a duct 41 to the other end of the cylinder, that is, the end that is closed by the head I I. The duct 46 comprises an L-shaped section 46a in an integral outwardly extending protuberance 48 along the cylindrical side wall 23.01D the valve supporting head I2 of the device and an L-shaped section 46h in the outwardly extending flange 25. The protuberance 48 is locatedbetween and at right angles to the fluid inlet 3U and the fluid outlet 3|. The duct 46 is adapted under control of the valve I3 to be connected to receive fluid under pressure from the inlet when the piston IU is adjacent to the cross-wall 22l of the head I2 so that the fluid flows therethrough into the cylinder in such manner as to cause the pisto-n to move towards the head I I. When the piston I3 reaches the end of its stroke in the direction of the head II the duct 4G is adapted under control of the valve, as hereinafter described, to be connected to the fluid outlet 3| so as to permit of discharge of the fluid in the cylinder during `the retractile stroke of the piston, that is, movement of the pis-- ton in the direction of the cross-wall 22. The duct 41 consists of an L-shaped section 41a in a protuberance 49 on the side wall of the valve supporting head I2 and a longitudinal section 41lo in a longitudinally extending lug 50 along one side of the cylinder 9. One end of the section 41:t joins or communicates with the groove 35 and the other end is aligned with"and joins the contiguous end of the section 41h. The other end of said section 41b extends inwards, as shown in the drawings, and leads to the end of the cylinder which is closed by the head I I.- The duct 41 is adapted under control of the valve to be connected by said groove 36 to the outlet 3| when the piston moves from the cross-wall 22 kto the cylinder head Il and permits of ready discharge of the fluid between the piston I0 and the head I I, and is further adapted undercontrol'. of the asserita valve, as hereinafter described, to be connected by way of-thegroove34 to the fluid inlet 30 when the piston reaches the end of its stroke inthe direction'of the head II in order that the fluid fromthe inlet is lpermitted to enterthe space between the piston and thev cylinder head I I and effect retractilemovementof thepiston, that is, movement in the directionof the cross-wall 22.

The plunger type valve lI3 is disposed in the valve chamber 29 and ts in the slideway 40 within the sleeve 31 so that it is slidable axially back-and forthlbetween the cross-wall 22 of the head I2 and the removable cap 21 at the outer end of'. the `side wall 22. It is cylindrical and embodies in the` outer periphery `thereof three laterally spaced comparatively wide grooves or cutoutsl,y 52 and 53. `The groove 52 is centrally disposed with respectto thevalve I3 and is separated from the grooves 5I and '53 by way of a pair of ,annular outwardly extending ribs 54 which vnt slidably within the slideway 40. The groove 52 is adapted when the valve is shifted into abutment with the cap 21, as shown in Figure l, tobridge the holes 42 and 43 in the sleeve 31 and elect communication between the fluid inlet and the duct 46. It is further adapted when the `valve is shifted into abutment withthe cross-wall 22 of the head I2, as shown in Figure 3, to bridge the holes 43` and 44 and effect communication between the fluid inlet 30 and the duct 41. The groove 53 is adapted when thevalve I3 is in abutment with the cap 21 to bridge the holes 44 and 45, as shown in Figure 1, and establish communication between the duct 41 and the outlet 3l. The groove ,5I at the other end of i the valve I3 is adapted when `said valve is in abutment with the cross-Wall 22 of the head I2 to bridge the holes 4I and 42, as shown in Figure 3, and thus establish or effect communication between the duet 4'6 and the outlet 3I. When the valve I3 is shifted into abutment with the cap 21 and the groove 52 in the valve is in bridged relation with the holes 4'2 and 43 of the sleeve and the groove 53 at the inner end of the valve i s in bridged relation with the holes 44 and 45, fluid under pressure flows through the inlet 3U, the holes 43, thegroove 52, the holes 42, the groove 33, and the duct v4I; into the space between the piston I0 andthe cross-wall 22 and operates to shift lthe piston toward the opposite end of the cylinder, that is, in the direction of the cylinder head I I. During such shift of the piston the spent iluid in the space between the piston IO'and said head II is released and flows out through the outlet via the duct 41, the holes 44, the lgroove 53, the holes 45, the groove 3B and the outlet chamber l39. When the piston reaches the end of its stroke and the valve I3 is shifted into abutment with the cross-wallA 22, as shown in Figure 3, the uid entering the device by way of the inlet 30 flows through the groove 34, the holes 43, the groove 52, the holes 44, the groove and the duct v`41 in'to the space between the piston I0 and the head II and operates'to return I or retract the piston, that is, shift it inthe direction of the cross-wall 22. During such shift of the piston the spent fluid in the space between the piston Ill and the cross-wall is released so that it'is discharged from the device by way of the duct 46, the groove 33, the holes 42, the groove 5I, the holes 4I, the groove 32, the outlet chamber 39, and the outlet 3|. From the aforegoing it is manifest that when the valve I3 is shiftedinto abutment with the cap 21 the fluid iscontrolled so thatitshifts the piston I Il towards ,In addition tothe cylinder 9 and the piston I,the\two heads II and I2, and the `valve I3, the device comprises apilot valve 55. This pilot valve is adapted to cause shift of the valve I3 at` the end, of each stroke of the piston and is slidably mounted in a longitudinal bore 56 in the central portion of `the valve I3. The end of the `pilot valvethat is remotely disposed with respect to the lpiston IU projects into a chamber 51 between the cap 21 and the adjacent end of the valve I3 and is provided with a head 58 which is secured in place by way of an externally threaded stern 59 in an internally threaded stem 59` in an vinternally threaded socket 60 in the pilot valve. Saidl head 5B is adapted when the pilot valve is shifted in the direction of the cross-wall 22 to strike against the adjacent end of the valve I3 and thus limit shift of the pilot valve relatively to said valve I3. The other `or innervend of the pilot valve is provided with a coaxial stem 6I. This stern` extends slidably through a bushing 62 in a bore or hole 63 in the central portion of .the cross-wall 22 of the valve supporting head I2 and is provided at the pilot valve end thereof with a head 64 and an externally threaded `part 65. Such part, as shown in `Figure 5, ts within an internally threaded socket, 66 in the inner endA of the pilot valveand serves xedly orvrigidly to connect the 4stem land pilct valve. The head 64 is disposed in achamber 31 in the inner end ofthe plunger typevalve I3 andis adapted in response to shift of the pilot valve toward the cap 21 to strike against the valve I3 and thus limit outward movement of the pilot valve relatively `to the plunger type valve I3. The Outer or other end of the stemSI extends into a longitudinal bore E8 in the inner end of the piston rod I5 and is provided with a head B9. This head is slidably mounted in the bore 58 'and forms a lost motion connection between the stem 6I and the piston rod and isadapted whenthe piston reaches the end of its stroke in the direction of the cylinder head II `to strike against the bushing 10 in the inner end of the piston rod and to shift the pilot valve in the direction of thefc'ross-Wall 22 and relatively to the plunger type valve I3, and is' further adapted whenthe piston I0 reaches theend of itsstroke in the 4direction of the cross-wall 22 to abut against the shoulder or cross-wall at the outer end of the bore 68 and elect shift :of the pilot valve towards the cap 21.,and relatively to the plunger type valve I3. The. bushing 10 is secured in place by way of a screw thread connection and constitutes a bearing for the outer end of the stem 5l for the pilot valve. The head 69 and the bore 58 constitute` a lost motion connection between the stern 6I and the piston rod I5 whereby the piston is permitted to move relatively to the pilot plunger except at the ends of its strokes when`the head 69 is brought into contact with Vthe bushing 1-0 or the crosswall at the outerend of the bore 68 and causes conjoint movement of the pilot valve and the piston, as hereinbefore pointed out. Shift of lthe `pilot valve 55 relatively to the main or plunger type valve I3 operates to control shift of Vsaid valve TIS, as Vhereinafter described. As shown in thexdrawings, the pilot valve is provided atone end thereof with a longitudinally extending centrally disposed passageway 1I,y and atits other end with a longitudinally extending centrally disposed passageway 12. These two passageways are separated by a central partition 13 which is formed as an integral. part ofthe pilot valve. The outer end of the passageway 1I leadsvto and communicates with a passage 14 in the head 64 at the inner end of the stem 6I and the inner end of the passageway 1I communicates with a plurality of holes 15 which extend transversely through the pilot valve and are adapted when said pilot valve is shifted in the direction of the cap 21 and relatively to the plunger type valve I3 to register with a pluralityof ports 16. The latter are formed in and extend transversely of the central portion of the valve I3 and lead to and communicate with the central groove 52 in said valve I3. The passage 14 is L-shaped and leads from the passageway 1I to the chamber 61 in the inner end of the valve I3. When the pilot valve is shifted in the direction of the cap V21 and relatively to the valve I3 as a result of the cross-wall at the outer end of the bore 61 striking against the head 69 at the outer end of the stein 6I when the piston reaches the end of its stroke in the direction of the head I2 the holes 15 are brought into registry with the ports 16. As soon as this takes place a portion of the iiuid under pressure which flows from the inlet 38 into the groove 52 in the central portion of the valve I3, flows through the ports 16, the holes 15, the passageway 1I, and the passage 14 into the chamber 64 and develops such pressure between the inner end of the valve I3 and the cross-head 22 that said valve I3 is shifted into abutment with the cap 21. Upon abutment of the valve I3 against the cap 21 the ilow of iiuid under pressure is reversed as far as the ducts 46 4and 41 are concerned with the result that the piston I0 is caused to move toward the cylinder head II. The passageway 12 communicates at its outer end with a passage v11 in the head 58'and this passage in turn leads to the chamber 51 between the cap 21 and the outer end of the valve I3. The inner end of the passage 12 communicates with a plurality of holes 18 which are located adjacent to the partition 13 and extend transversely through the pilot valve 55. The holes 18, as sho-wn in Figure 3, are adapted when the pilot valve is shifted in the direction of the cross-wall 22 and relatively to the valve I3 to register with the ports 16 in the central portion of the valve I3. When thel pilot valve is so shifted, as a result of the bushing 18 striking against the head 69 when the piston reaches the end of its stroke in the direction of the cylinder head II, a portion of the fluid under pressure entering the groove 52 from the fluid inlet 38 iiows through the ports 16. the holes 1, the passageway 12, and the passage 11 into the chamber 51 and develops sufficient pressure between the capy 21 and the outer end of the valve I3 to cause the valve to shift into abutment with the cross-wall 22 and effect such a reversal of the iiow of the iiuid under pressure through the ducts 46 and 41 that the piston is caused to move' or slide toward the cross-wall 22. The partition 13 serves to prevent uid under'pressure from flowing into the passageway 1I when the holes 18 are in registry :with the ports 16` and also serves to prevent iiuid under pressure from iiowing into the passageway 12 whenl the holes 15 are in registry with the ports 16. In order to vent the chamber 61 and thus relieve the pressure therein and permit the plunger typevalve I3 to 4be shifted into abutment with thecross-wail 22 in response to shift or the pilot plunger towards the cross-wall 22. as the result oi Contact at the bushing 1U with the head 69 at the end of the `stroke of the piston in the direction o1' the cylinder head Il, the pilot plunger is providedwith a plurality of Vent holes 13. l 'lhese holes are disposed between the holes 'la and the head oli and are adapted when the pilot valve is shifted in the direction of the crosswall 22 relatively to the valve1l3 to register with vent ports 8U in said valve I3. The ports 80, as shown in Figure 5, extend transversely through the inner end of the `valve I3 and lead to the groove 53 which, as hereinbefore described, communicates with the fluid outlet 3| via the holes 45 in the sleeve-31 andthe groove 36 in the side wall of the valve supporting head I2. When the pilot valve 55 is shifted inthe direction of the cross-Wall 22 at the end ofthe stroke of the piston in the direction of the cylinder head II iiuid under pressure is admitted into the chamber 51 as the result of registry of the holes 18 with the ports 16, and the vent holes 19 move into registry with the vent ports and vent the chamber 61 with the result that the Valve I3 is released for shift in the direction of the cross-wall 22 by the pressure within the chamber 51. In order to vent the chamber 51 when the pilot valve 55 is shifted in the direction of the cap 21 preliminary to shift of the main or plunger type valve I3 into abutment with said cap, the pilot valve is provided with a plurality of vent holes 8|'. These holes are disposed between the holes 18 and the head 58 and are adapted when the pilot plunger is shifted towards the cap and relatively to the valve I3'as the result of contact of the cross-wall at the outer end of the bore 68 with the head 69 atthe outer end of the stem 6I to register with vent ports 82 in the outer portion of the valve I3. Said vent ports 82 extend transversely of the valve and lead to the groove 5I, which, a's heretofore mentioned, communicates with the uid outlet 3l by way of the holes 4I in the sleeve 31, and the -groove 32 in the side wall of the head I2. When the pilot valve 55 is shifted towards the cap 21 atthe end of the stroke of the piston I 8 Ain the direction of the cross-wall 22'the fluid in the chamber- 51 is free to pass via the passage 11, the passageway 12,'the vent holes 8|, the vent ports 82, the groove 5I', the holesy 4I, and lthe groove 32 to the outlet 3| and as a result the valve I3 is released so that itmoves into abutment with the cap 21 in responseto the iiow of uid under pressure from the groove 52 into the chamber 14 at the innergend'rof said valve I3. From the aforegoing it is apparent that movement of the piston is controlled by shift of the plunger type valve I3 andthat the latter is controlled by the pilot valve 55 sothatfits position is changed at the end of each stroke of the piston.

`Assuming that the various parts of the device areY positioned, as shown in Figure 1, that is, the `piston is at the end of this stroke in thedirection of the cross-wal1'22and is ready to return toward the cylinder head- II and the Valve I3 is in abutment with the cap 21 and the pilot valve is so shifted in the direction of said cap that the head 64 is in abutment with the inner end of the valve I 3, and 'also assuming that uid under pressure is being delivered or supplied to the inlet 30, the operation of the device is as follows: The fluid under pressure entering the inlet 30 ows through the groove 34 in the central portion of the side wall of the head I2 and the holes 43 in the central portion of the sleeve 31 into the annular groove 52. From this groove a portion of the fluid fllows through the ports 16, the holes 15, the passageway 1I, and the passage 14 into the chamber 51 and serves to maintain the plunger type valve I3 in'abutment with the cap 21. The remainder of the fluid under pressure iiows from the groove 52 through the holes 42 and the groove 33 to the duct 46 and thence through the duct into the space between the piston I and the cross-wall 22. In response to the pressure of the fluid within this space the piston Il) is caused to move in the direction of the cylinder head II. During such movement of the piston the spent uid in the space between the piston IIJ and the head II flows to the outlet 3l via the groove 35, the holes 44, the groove 53, the holes 45, the groove 36 and the discharge chamber 39, as hereinbefore described. At the end of the stroke of the piston in the direction of the h ead II, the bushing 10 in the inner end of the piston rod I5 strikes against the head 69' at the outer end of the stem 6I and through the medium of the stem shifts the pilot valve 55 in the direction of the cross-wall 22 and rela-l tively to the main valve I3. As soon as the pilot valve is so shifted, the chamber 61 is automatically vented, as the result of registry of the vent holes 19 withthe vent ports 80, as shown in Figure 2, and fluid under pressure ows through the ports 16, the holes 18, the passageway 12, and the passage 11 into the chamber 51. Upon'entry of the fluid into this chamber pressure is developed which causes the main valve I3 to shift or move into abutment with the crosswall 22 (see Figure 3). As soon as the valve I3 comes in contact with the crosswall 22 the flow of iiuid through the ducts 46 and 41 is reversed. The iiuid under pressure entering the groove 52 via the groove 34 and the holes 41 instead of flowing through the holes 42 and the groove 33 to the duct 45 flows through the holes 44 and the groove 35 to the duct 41 and thence through this duct to the space between the piston ID and the cylinder head I I. Upon entry into this space the iiuid as the result of its pressure forces the piston II) in the direction of the cross-wall 22. During shift of the piston II) in the direction of said cross-wall 22 the spent fluid in the space between the last two mentioned parts of the device flows through the duct 46, the groove 33. the holes 42, the groove 5I, the holes 4I, the groove 32 and the discharge chamber 39, to the outlet 3l. During shift of the piston IIJ towards said cross-wall 22, the chamber 61 as the result of the position of the pilot plunger remains vented and pressure is developed in the chamber 51 tending to hold the valve I3 in abutment with the cross-wall 22, as shown in Figure 3. When the piston I0 reaches the end of its stroke in the direction of the cross-wall 22 the cross-wall vor shoulder at the end of the bore S8 strikes against the head 69 and shifts the pilot valve in the direction of the cap 21 and relatively to the valve I3. In response to such shift of the pilot valve the chamber 51 becomes vented as the result 0f registry of the vent holes 8l with the vent ports 82 and fluid under pressure is caused to flow through the ports 16, the holes 15, the

passageway 1I and the passage 14, into the chamber 61. As soon as the fluid enters this chamber the valve I3 is shifted into abutment with the cap 21 and the ducts 45 and 41 are controlled so that the flow of uid therethrough is again reversed and the piston I is caused to travel in the direction of the head II. When the plunger type valve I3 shifts back and forth between the cap 21 and the cross-wall 22 as the result of control by the pilot valve 55, the pilot valve moves with it, as shown in Figures 2 and 3.

The herein described fluid pressure operated device is extremely eflicient in operation and is characterized by the fact that the main or plunger type valve I3 when shifted into either of its two positions remains in such position until the piston reaches the end of its full operating stroke and causes shift of the pilot valve. Because of the foregoing the piston can assume no dead center position whatsoever and hence is caused at all times to reciprocate in response to supply or delivery of fluid under pressure to the inlet 3i). By having what may be termed a full port opening of the main or plunger type valve at all times the piston reciprocates within the cylinder at a uniform rate of speed. The device is further characterized by the fact that the pressure of the uid around the main and pilot valves is uniformly distributed and hence there is no tendency for the valves to bind. In addition to being efcient in operation the device is compact and capable of being produced at a low and reasonable cost. If desired the device may be utilized to effect reciprocation of an operating part of an associated mechanism or it may be used as'a medium for measuring a liquid into predetermined quantities as the result of the reciprocating action of the piston.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claim, without departing from the spirit and scope of the invention.

Having thus described the invention what I claim as new and desire `to secure by Letters Patent is:

A fluid pressure operated device comprising a cylinder having closing means at the outer end thereof; a head serving to close the inner end of the cylinder and provided with a closed ended elongated cylindrical valve chamber disposed outwardly of, and in coaxial relation with, the cylinder. and provided with rst, second, third, fourth and fifth spaced apart annular grooves facingand communicating with the chamber and running in order from the outer end of said chamber to the inner end, and in addition an inlet for uid under pressure leading to the third groove and a fluid outlet leading from the rst and fifth grooves; a piston mounted in the cylinder for sliding movement between the ends thereof and provided with a rod extending slidably through the said closing means; means associated with the head and cylinder forming a pair of separate ducts extending one between the second groove and said inner end of the cylinder and the other between the fourth groove and said outer end of the cylinder; a cylindrical plunger type sleeve-valve slidably mounted in theychamber, provided with first, second and third external spaced apart annular cutouts running in order from the outer end of the valve to the inner end, embodying holes leading respectively from the three cutouts to and through its interior surface, and adapted when shifted to the outer end of the chamber to have the first cutout register with the first groove, its second cutout bridge and establish communication between the second and third grooves, and the third cutout bridge and establish communi cation between the fourth and fifth grooves in order to cause shift of the piston in the direction of the outer end of the-cylinder by the uid under pressure entering the inlet and flowing' through said one duct, and when shifted tc the inner end of said chamber to have the rst cutout bridge and establish communication between the rst and second grooves, its second cutout bridge and establish communication between the third and fourth grooves, and the third cutout register with the fth groove in order to cause fluid under pressure to ow through said other duct and effect reverse shift of the piston in the direction of the inner end of the cylinder; and means for automatically intro-v d ucing fluid under pressure into the outer end of the valve chamber and venting the inner end of said chamber when the piston reaches the end of its stroke in the direction of the outer end of the cylinder in order to cause shift of the plunger type valve to said inner end of the valve chamber and for introducing fluid under pressure into said inner end of the Valve chamber and venting said outer end of the Valve chamber when the piston reaches the end of its stroke toward the inner end of the cylinder in order to cause shift of the plunger type valve to said outer end of the valve chamber, embodying a sleeve type pilot valve slidably mounted in the tudinal passage and transverse inlet and outlet opening leading therefrom, and an inner vlongitudinal passage with transverse inlet and outlet openings leading therefrom, and adapted to be shifted inwards toward the inner end of the valve chamber when the piston reaches the end of its stroke toward the outer end of the cylinder and to assume a position wherein the inlet opening leading from the outer passage registers with the hole leading from the second cutout, the outlet opening leading from the outer passage is closed, the inlet opening leading from the inner passage is closed, and the outlet opening leading from the inner passage' registers with the hole leading from the third cutout, and further adapted to be shifted outwards towards the outer end of the valve chamber when the piston reaches the end of its stroke towards the inner end of the cylinder and to assume a position wherein the inlet opening leading from the inner passage registers with the hole leading from the second cutout, the outlet opening leading from the inner passage isl closed, the inlet opening leading from the outer passage is closed and the outlet opening leading from said outer passage registers with the hole leading from the rst cutout, and a lost motion connection between the pilot valve and the piston rod arranged so that it shifts the pilot valve towards the inner end of the valve chamber when the piston 'reaches the end of its strokey towards the outer end of the cylinder and also to shift the pilot valve outwards toward the outer end of the valve chamber when the piston reaches the end of its stroke toward the inner end of said cylinder'.

CHARLES A. FINK. 

